The present invention relates to a disc brake for automotive vehicles comprised of a movable brake housing straddling the brake disc in a manner like a caliper and having a hydraulic actuating unit for the brake linings, and of a retaining element or for the housing, with the holder being coupled to an element of the wheel suspension.
A disc brake housing includes a brake carrier and a brake housing. In a known spot-type disc brake (as in German patent document DE 38 08 139 A1), one end portion of the spring clip is supported in the brake carrier which is provided with two brake carrier arms interconnected through a connecting web. After the brake lining is inserted, the spring clip is turned over so that it moves into abutment with one section on the brake lining. The other end portion of the spring clip is then slipped beneath the connecting web. For the assembly, the spring clip is therefore required to be pressed down in the direction of the brake lining to the extent that the other free end can be inserted beneath the connecting web. Considerable mounting forces must be generated to achieve this operation. The disc brake discussed herein is of the so-called-"fist"-caliper-type brakes which straddle the respective brake discs from the inside. This type of disc brake which is employed in modern high-power passenger cars offers the advantage of increasing the effective disc radius and of reducing the thermal load.
German patent application No. 3,508,039 discloses an internally straddling disc brake for automotive vehicles. The known device includes a brake disc which is mounted at its outer edge, a stationary brake carrier, a brake housing which is axially slidably supported at the brake carrier by means of a pin guide and is actuatable by means of an actuating device and which straddles the inner edge of the brake disc. Two radially extending webs and a bridge section extending substantially in axial direction and interconnecting the former are provided. A first brake lining which is positioned and supported in the brake carrier on one side of the brake disc and which is directly actuatable by the actuating device and a second brake lining is positioned and supported at the brake housing on the other side of the brake disc and is actuatable by the adjacent web of the housing.
According to the noted German patent application, it is proposed that the pin guide be furnished with a carrying pin being configurated in the shape of a fixed bearing which absorbs any major circumferential forces transmitted by the second brake lining through the brake housing to the guide. The pin is rigidly coupled to the brake carrier or the brake housing and engages a guide bore in the brake housing or in the brake carrier, and the carrying pin is positioned in the range of the radial extension of the brake disc.
The present invention has the following objects: A space-saving solution is to be provided for the brake. The assembly space determined by the vehicle manufacturer is utilized to the maximum extent possible. The connecting web positioned radially externally and which is required in the known systems is eliminated. It is, furthermore, an object to increase the effective radius of the brake even more than in the known systems and to reduce the thermal load of the brake to an extent still greater than in the known devices.
On the whole the brake is to become more of a compact-design. The rumbling tendency and generation of other noise are to be reduced. The invention is to provide a greater ease of servicing. The linings are removed and the brake disc is exchanged easily and without disassembling the caliper. The piston-side, that is to say, the internal lining becomes a trailed lining, as a result of which favorable conditions are created for the transmission of the elevated tangential forces occurring in the course of braking. A spot-type brake is provided wherein the internal lining can be mounted more easily and can be retained by a spring.
It is, then, an object of the present invention to achieve an elevated stiffness of the holder and the housing while being of a weight which is lower than that of known brakes. On the other hand, the supporting lug is to be massive and not in the shape of fingers. On account of the material accumulation, a massively designed supporting lug offers the advantage of a reduced noise. The assembly of the brake in the vehicle is to be simplified in accordance with the present invention.
In addition, the holder is to offer ease of tooling relative to known devices. Improvements are provided by the present invention for the casting of the housing. Moreover, expensive and cumbersome milling operations for the fabrication of the lining supports are avoided.
The assembly of the disc is to be simplified. This means that it is achieved that the leaving-side lining support at the holder is eliminated, so that the disc will more easily allow insertion during assembly. Simultaneously, use is made of a thicker lining mass.